Liver cancer is the fifth most common cancer worldwide. More than 400,000 cases were reported in 1990. Hepatocellular carcinoma (HCC) accounts for 80% of all liver cancer. Liver cancer can result from both viral infection and chemical exposure. Known risk factors include hepatitis B and C virus infection and exposure to aflatoxin 1. It is not known whether distinct routes to liver cancer affect the same or different cellular pathways. No mutational model has yet been developed for liver cancer as it has been for other cancers such as colon cancer. The molecular events that precede neoplastic transformation of the liver are not well understood. With no clearly identified cause, successful treatment options are lacking. In fact, the specific genes that are deregulated in liver cancer have not yet been enumerated. This is a critical first step in developing a successful strategy for treating liver cancer.
There is a pressing need to understand the molecular events associated with development of liver cancer, both in humans and in animal model systems where liver cancer is extensively studied, and to provide diagnostic and therapeutic reagents for treating same.